[Chris V]

The only way to lubricate the apex seals of the wankel is to inject oil into the combustion chamber. ALL rotaries do it (other than the ones converted to run on pre-mix), so all rotaries use oil. There are oil control seals to keep it from using too much, and it sounds like those may be getting tired, or need to be driven on more to seal up better at high rpms. But yes, oil use is normal.